Average True Range

Average True Range is the most useful indicator most retail traders ignore. It does not have an exciting signal. It does not blink overbought or oversold. It does not cross any line. It just plots, accurately, how much a typical bar moves.

That single number is more valuable for actual trading outcomes than the entire momentum-indicator family combined. Position sizing, stop placement, and target sizing all depend on knowing the typical move size. ATR gives you that number directly. Almost every other piece of the trade structure rests on it.

What ATR actually measures

ATR was developed by J. Welles Wilder Jr. and published in his 1978 book New Concepts in Technical Trading Systems - the same book that introduced RSI, ADX, and Parabolic SAR. The premise: traditional volatility measures (like standard deviation) ignore gaps, while gaps are often the largest single-bar moves a market makes. Wilder defined "true range" specifically to include them.

The "true range" of a single bar is the largest of three values:

1. Today's high minus today's low
2. Absolute value of today's high minus yesterday's close
3. Absolute value of today's low minus yesterday's close

If a market opens with a gap up, the gap from yesterday's close to today's high is captured by option 2. If it opens with a gap down, option 3 captures the move from yesterday's close to today's low. Standard "high minus low" misses these. True range does not.

ATR is the moving average (Wilder's smoothing) of true range over N bars. The result: a number, in price units, that says "the typical bar moved this much."

The formula

True range (TR) for each bar = max(High - Low, |High - Prior Close|, |Low - Prior Close|)
ATR(today) = ((ATR(prior) × (N - 1)) + TR(today)) / N

The first ATR value is computed as a simple average of the first N true range values. Each subsequent bar updates using Wilder's smoothing (the same recursive formula used in RSI).

ATR is reported in the same units as price. A stock priced around $100 with a 14-period ATR of 2.00 has bars that typically move 2 dollars from extreme to extreme. A futures contract with an ATR of 50 ticks has bars typically moving 50 ticks. A currency pair with an ATR of 80 pips has bars typically moving 80 pips.

A worked example

Suppose yesterday's ATR (14-period) settled at 2.00 on a stock around $100. Today's bar prints:

High: 104.50
Low:  101.80
Yesterday's close: 102.00

Compute the three candidate true ranges:

1. High - Low = 104.50 - 101.80 = 2.70
2. |High - Prior Close| = |104.50 - 102.00| = 2.50
3. |Low - Prior Close|  = |101.80 - 102.00| = 0.20

Today's true range is the max of those three: 2.70.

Update ATR with Wilder's smoothing:

ATR(today) = ((2.00 × 13) + 2.70) / 14
           = (26.00 + 2.70) / 14
           = 28.70 / 14
           ≈ 2.05

The ATR ticked up from 2.00 to 2.05, reflecting that today's bar was slightly larger than the average. If today had been an inside day with a true range of 1.50, ATR would have ticked down to 1.96 instead.

How traders actually use ATR

Three uses generate consistent edge. Anything else is misapplication.

1. Stop-loss sizing

This is ATR's killer application. Multiply ATR by a factor (1.5×, 2×, or 3× are common) and place your stop that distance from your entry.

Example: you enter long on a $50 stock with an ATR of 1.00. A 2× ATR stop places your stop at $48. In a calm market, that's a workable distance. If the same stock had an ATR of 2.50 (high volatility), the same 2× ATR rule places your stop at $45 - much wider, but appropriate for the regime.

The dollar amount risked stays constant (because you size the position smaller in the high-volatility case), but the stop adjusts automatically to current conditions. You stop getting stopped out by noise in volatile markets, and you do not give back unnecessary room in calm markets.

This is the single biggest reason professional traders prefer ATR-based stops to fixed-dollar or fixed-percentage stops.

2. Position sizing

If you risk a fixed dollar amount per trade (say 1 percent of account, or $500 on a $50,000 account), and you use an ATR-based stop, your position size becomes:

Position size = Risk per trade / (ATR × multiplier)

A 2× ATR stop on a stock with ATR of 1.00 means your stop is $2 away from entry. To risk $500, you trade 250 shares. If ATR was 2.50, the same dollar risk gets you 100 shares.

Same dollar risk, fewer shares in volatile markets, more shares in calm ones. Position sizing adapts to regime automatically.

3. Volatility regime detection

ATR rising sharply over consecutive bars = volatility expanding. Often happens around news, earnings, or breakouts.

ATR falling steadily = volatility contracting. Often happens in coiling phases before a breakout. A multi-week low in ATR is one of the cleanest signals that a directional move is overdue.

Use ATR contraction as a watchlist signal (which instruments are coiling?), not an entry trigger.

The trap most retail traders fall into

The trap is not misusing ATR - it is ignoring it.

Most retail traders use fixed-dollar stops ("I will risk $200 per trade") or fixed-percentage stops ("I will use a 3 percent stop") regardless of the instrument's current volatility. The result: their stops are too tight in volatile markets (they get stopped out by noise) and too wide in calm ones (they give back unnecessary room).

ATR-based stop sizing makes this problem disappear. The single most useful change most retail traders can make to their P&L is switching from fixed stops to ATR-based stops. It does not require new indicators, new strategies, or new platforms. It is one math change.

The second trap (smaller, but real): using ATR as an entry trigger. Some courses teach "buy when ATR spikes." This is incoherent - ATR is direction-agnostic. A spike in ATR means the bar is large, but it does not say which way. ATR is for sizing trades, not finding them.

ATR vs other volatility measures

vs Standard Deviation (used by Bollinger Bands). σ measures dispersion of closes around their mean. ATR measures the size of typical bars including gaps. ATR is more responsive to news-driven gap moves; σ is smoother. For stop-sizing, ATR is preferred; for visualizing volatility regime around a moving average, σ (via Bollinger) is preferred.

vs Average Daily Range (ADR). ADR is simply (high - low) averaged over N days, ignoring gaps. Cleaner conceptually, but loses information when gaps matter (overnight stocks, weekend forex, news events). ATR is more accurate; ADR is sometimes preferred by traders who specifically want gap-excluded readings.

vs VIX (volatility index). VIX measures forward-looking implied volatility from S&P 500 options. ATR measures backward-looking realized volatility from price bars. They correlate but are not interchangeable. VIX is one number for the broad market; ATR is per-instrument.

Common questions

What is a "good" ATR value? Not a meaningful question. ATR is contextual to the instrument and the timeframe. ATR of 5 on a $50 stock is enormous (10 percent daily range); ATR of 5 on Bitcoin trading at $100,000 is negligible. Always interpret ATR relative to price.

Should I change the 14-period default? Usually no. 14 is the universal convention and balances responsiveness with smoothing. Shortening to 7 makes ATR more reactive but noisier; lengthening to 21 smooths but lags. Stay with 14 unless you have a specific reason.

Does ATR work on intraday charts? Yes, and especially well. Intraday ATR (on 5-minute or 15-minute bars) is what active day traders use for intraday stop sizing. The same ATR-multiple logic applies, just at a different timeframe.

Why is ATR sometimes higher on a chart than the actual recent bars look? Because ATR includes gaps. If the market gapped up overnight and then traded a narrow intraday range, the gap from yesterday's close gets counted in the true range calculation. ATR reads "higher than the visible bars" because the gap is real volatility even when it does not show up in the bar itself.

Can I use ATR for targets, not just stops? Yes. A common target rule: take partial profit at 2× ATR profit, hold the rest with a trailing 1× ATR stop. The same volatility framework that sizes the stop also sizes the expected typical move.

What is the Chandelier Exit? A trailing-stop rule that uses ATR. Trailing stop = highest high since entry - (3 × ATR). The stop trails up as the market makes new highs, sized in ATR units. It is one of the cleanest mechanical trailing-stop rules and is fully ATR-based.

When to use ATR and when not to

Use ATR when:

• You are placing any stop on a trade (and you should be on every trade)
• You are sizing position size by dollar risk
• You need to compare volatility across instruments or timeframes objectively
• You are scanning for low-ATR coiling setups ahead of breakouts

Skip ATR when:

• You are looking for an entry signal - ATR does not provide direction
• You are comparing ATR readings across instruments without normalizing for price (5 on a $50 stock is not the same as 5 on a $5,000 stock)
• You are layering multiple ATRs on the same chart - one is sufficient